The present invention pertains to novel structural laminates and their production.
Various structural laminates have been proposed and used. In the past, stiffened laminates have been made by first forming a primary laminate consisting of several layers of resin impregnated fabric. The primary laminate was cured or completed and then a stiffening rib or bead, usually of honeycomb core, was applied or attached to the primary laminate with glue or adhesive, which attachment involved scuffing the surface of the primary laminate with a grinder so that the adhesive could bond, and then locating and holding the stiffener rib in the proper place until the adhesive cured. The present invention eliminates the aforementioned multiplicity of steps in a surprisingly simple manner, and eliminates the need for grinding and the use of the adhesive altogether.
Another disadvantage or prior laminates is their relatively great weight, as compared with a reinforced laminate constructed in accordance with the teachings of the present invention.
The gist of the present invention is a new structural laminate and method of forming same, preferably using honeycomb core with single cover sheets for the primary structure together with honeycomb core reinforcement strips, with the core or cores preferably being crushed during the step of lamination, and with the primary laminate structure and the reinforcement being formed and bonded in one operation. More particularly, this invention is directed to the concept of mold-forming stiffener honeycomb core beads to a primary structure laminate simultaneously with the molding of the primary structure formed of a reinforced fiber plastic. It is believed that this invention represents a major advance in a crowded art, which will result in its widespread adoption . . . particularly in the aircraft industry.